US106989A - Improvement in wood pavements - Google Patents

Description

A: BETTELEY. WOOD PAVEMENT- No. 106,989. Patented Sept. 6, 1870 in: mm Perms co, noYaumo wAsqmumm o r strut mjifliw ALBERT BETTELEY, OF BOSTON, MASSACHUSETTS.

Letters Patent No. 106,989, dated September 6, 1870.

IMPROVEMENT IN WOOD PAVEMENTS.

."he Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern I Y Be it known that I, ALBERT BETTELEY, of Boston, in the conntyof Snfiolk and State of Massachusetts, have invented a new and useful Improvement 1 in Pavements; and I do hereby declare that the following, taken in conncctiori with the drawing which accompanies and forms part of this specification, is a description of my invention sufficient to enable those skilled in the art to practice it.

This invention consistsin' a pavement in which the blocks composing it are equally screw-threaded on their peripheries, so that, when placed in position on a road-bed, the threads 'on the adjacent blocks inter lock, and the blocks thus mutually support each other, and so that, when any portion of the pavement has to be removedfor laying pipes, sewers, 850., or for repairs or changes of any kind, enough blocks may be taken vertically from their places, by turning them axially in the proper direction, to leave an open space, so that the majority of blocks 'to be removed can be freed from contact with the other blocks by lateral movement;

This pavement I consider as an improvementupon, but subordinate to the pavement patented to me Marcln29, 1870, under the number 101,346, and I design to construct it of wood cylinders formed from young trees, thouglrI do not consider my invention as necessarily limited to any special material of which 'I may form the srr'ew-tln'eaded pavement-blocks.

In constructing screw-threaderl blocks of wood from which to make my improved pavement, I propose to take the bodies of young trees of such length as can be conveniently turned in a lathe, and then, by means of a carriage moving at a fixed rate, with reference to the rotations given to the wood, I pass two tools along the wood, the tool in advance operating to reduce the wood to a givendiameter, and the tool which follows operating to cut into the cylinder the thread of a screw, or, in other words, cutting a spiral groove along and into the wood, leaving the thi'eads projecting, These tools may be made to rotate, if' desired, like the cutters commonly used in turning-lasts.

The wood thus shaped is cut into short pieces of the required length, say from sixinches to a foot, and if desired, one end of each block may be made of any desirable amount of convexity.

In assembling these blocks on a road-bed, six of them surround a seventh, and the threads of the seventh interlock with the threads formed on each of the six, and each of the six forms the seventhof a surrounding group of six, and this will be the system throughout a pavement, except at theborders thereof, as at edge-stones or crosgngs, 85c.

' At the pavement boundaries some of the blocks will have to be cut, generally into halves, though some quarter blocks may be required at corners or angles.

In closing up a space covered with screw-threaded blocks which have been made to interlock by pushing them laterally against each other, the last blocks will be screwed into the spaces left for them between the surrounding blocks.

This operation will be easily performed by making use of a cross-handled or cranked shaft, having at its other end spurs or teeth, which may be inserted into holes formed in the tops of the screw-threaded blocks, or which may be'driven into the wood, and the same tool or implement may be used for removing blocks from the assembled pavement.

In the drawing Figure 1 shows in plan a group of pavementblocks, illustrative of my invention, and

Figures 2 and 3 exhibit the same in elevation.

The form given to the screw-threads may be varied, to suit the requirements of the material and location.

The form shown in fig. 3 is that which I deem best adapted for blocks of wood.

I claim- A pavement in which the blocks composing it have Witnesses:

J. B. OROsBY, FRANCIS GOULD.

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